.thetalibanclaimedresponsibility for the attack but there's doubt about the rebel group's involvement. >>> in a moving white house ceremony president obama awarded the nation's highest military honor to army sergeant first class leroy petrie for bravery in the line of fire. petrie's actions cost him his right hand but he saved the lives of his comrades. >> reporter: above and beyond. at's where leroy petrie went in may 2008. afghanistan, his seventh tour of duty. these pictures from before he found out what he was made of. with the true sign of that today being a ceremony, a certain discomfort at the attention. >> to be singled out is very humbling. >> reporter: perhaps, yes, for a kid who used to get into fights and who almost failed in high school. but who out there picked up a live enemy grenade to toss it away to save his comrades. it cost him his right hand. but he's alive, rare for medal of honor winners who usually are honored posthumously. but there's also this. leroy petrie decided he's not done. and when he reenlisted he took the oath with his right hand. his new one. john d